Delayed action mechanical rope cutter



y 22, 1958 E. e. RICHARDS 2,343,933

DELAYED ACTION MECHANICAL ROPE CUTTER Filed Jan. 15, 1958 United States Patent@ DELAYED ACTION MECHANICAL ROPE CUTTER Ernest G. Richards, Alamogordo, N. Mex.

Application January 15, 1958, Serial No. 709,124

4 Claims. (Cl. 30182) (Granted under Title 35, U. S. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the United States Government for governmental purposes without payment to me of any royalty thereon.

The subject invention relates to devices for releasing a load from a balloon, parachute, airplane or the like and more particularly to a mechanical rope cutting device to act after a lapse of time.

It is frequently necessary to release a load, such as an instrument or a ballast from a plane, parachute, and particularly from a balloon, after a predetermined lapse of time, the interval being measured in seconds, minutes and sometimes hours. There are several devices for releasing a load or opening a parachute after a time delay or the happening of an event. Some are electrical, some employ the burning of a powder train or the escape of gas through a restricted orifice for the timing mechanism and use various devices for releasing the load such as opening a catch, firing a pellet through a line by means of gunpowder or cutting it with a knife.

It is an object of this invention to provide a certain and sure mechanical means for releasing a load after a predetermined interval of time and after all other devices have failed.

It is a further object of this invention to provide such reliable means in a simple and easily adjusted device which is economical and easy to manufacture.

Essentially, the device consists of a clock work mechanism driving a cam which after a lapse of time releases a spring driven knife to sever the restraining load line or cord.

Referring to the figures:

Fig. 1 is a sectional view showing the essential features of the device; and

Fig. 2 is a diagram showing the device in use.

In the drawings the numeral 10 indicates the body or frame which may be formed of any suitable metal. A piston 11 is arranged in an annular groove in the frame 10 and carries a cutter blade 12. A tensioned compression spring 15 is arranged to urge the piston 11 to the left so that, when released, it will drive it past rope guide 13 to stop 14. The piston 11 is prevented from movement by a trigger mechanism including a sear pin 16. The piston 11 may be pulled back into position by cocking handle 26.

Sear pin 16 is tensioned by a spring 17 which biases it against a scar lever 18 and away from the groove 11 in the piston 11. The scar lever 18 is prevented from moving by the shoulder 19 of the sear 19. The lever 18 and the sear 19, are pivoted on pins 25 and 25' respectively. Pins 28 are used for attaching the clock work mounting ring 29 to the frame 10. The scar 19 is urged away from the supported end of the lever 18 by a pin 20 tensioned 'by a spring 22 but is held in place by contact of a roller 23 with the edge 24' of a cam 24.

'ice

The cam 24 is rotated by clock work (not shown) which may be supported by a mounting ring 29. The numeral 30 designates the complete device and is shown in Fig. 2 in use between a balloon 31 and a load 32 to be dropped.

The device operates as follows:

When the cam 24 has been rotated sufficiently, the spring 22 moves the pin 20 to the left against the sear 19 which is now free to move to the left as shown in Fig. 1. This permits release of the lever 18 to the dotted line position shown in Fig. l by the compression spring 17. The scar pin 16 is moved out of the slot or groove 11 in the piston 11. The compression spring 15 is thus released and drives the cutter blade 12 through the load line held in guide 13 thus severing it and causing the load 32 to drop.

It is obvious that this invention is a simple, straightforward mechanical rope cutter as reliable in its action as the accuracy and dependability of the clock mechanism with which it is associated. Such timing mechanisms have been developed to a high state of perfection and can be depended on under all Weather conditions if properly housed. The time delay in this invention can be regulated not only by the gear ratio which drives the cam but by the degrees of arc on the circumference of the cam itself. Thus the time delay can be quickly adjusted by the use of interchangeable cams of varying degrees of arc.

What I claim is:

1. In a cord cutting device, a movable cutter member, a member cooperating with said movable cutter for severing a load carrying cord, means for positioning said cord between said members, means normally biasing said movable cutter toward said cord and said cooperating member, and rotating time controlled means for permitting movement of said movable cutter member to sever said cord at the expiration of a predetermined time interval.

2. In a cord cutting device, a movable cutter member, a stationary member cooperating with said movable cutter member for severing a load carrying cord, means for positioning said cord between said members, spring means for biasing said movable cutter member toward said cord and said stationary member, lever controlled means for maintaining said cutter member in biased position, and a clock operated cam for permitting release of said lever controlled means to permit said spring means to move said movable cutter to sever said cord at the expiration of a predetermined time interval.

3. In a cord cutting device a cutter blade fixed in a movable piston, a stationary member opposing said cutter blade, means for positioning a load carrying cord between said cutter blade and said stationary member, a spring means biasing said movable piston toward said stationary member, a sear pin holding said movable piston in place, a scar lever controlling said sear pin and connected through a releasing means to a clock work driven cam to release said piston and cutter blade to sever said cord after a predetermined lapse of time.

4. In a delayed action mechanical cord cutter the combination of a cutter blade mounted in a spring loaded movable piston, a stationary stop opposite said cutter blade, means for positioning a load carrying cord between said cutter blade and said stop, a lever means controlling a scar pin holding said movable piston in place, a releasing means connecting said lever to a clock work driven cam to release said cutter blade to sever the said load line after a predetermined time interval.

No references cited. 

